.box1:nth-of-type(1){
    width: 470px;
    min-height: 300px;
    float: left;
    margin-right: 10px;
}
.box1:nth-of-type(2),.box1:nth-of-type(3){
    width: 240px;
    min-height: 230px;
    float: left;
}
.box1:nth-of-type(4),.box1:nth-of-type(5){
    width: 240px;
    min-height: 230px;
    float: left;
}